Greg says that every time he joins a coffee shop network with his laptop, the internet dies. Leo says that there could be an issue with the Wi-Fi radio on the laptop that's causing it. It could also be an issue with the Coffee shop's DHCP.
The Chatroom suggests disabling the Wi-Fi network in control panel, rather than the "button," to see if the issue persists. Then the only thing he can do is check to see if there's another program that's running in the background that could be disrupting his connection. Leo says it's a strange interaction between the laptop and the router using DHCP. It's been a problem with Apple tablets and laptops of late.
Jim in San Diego suggests making sure he doesn't have internet connection sharing turned on. Others in the chatroom say it's an issue with the router as well.